Bone fixation device

Abstract

A bone fixation device for use in, for example, spinal column surgery, includes at least two bone fixation elements that each have a passage and a portion to be anchored on or in the bone. The device also includes at least two longitudinal, flexible connecting members that can be inserted and fastened in the passages of two adjacent fixation elements. The device can flexibly adapt to a patient's anatomy and to desired surgical results during the implantation of the device, and can then be rendered entirely rigid by simply blocking the fixation elements relative to one another. In addition, use of the device in the surgical treatment of the spinal column is minimally invasive.

1 . A bone fixation device comprising: 
 at least two bone fixation elements, each having a passage and an anchoring portion operative to be anchored on or in the bone; and    at least two longitudinal, flexible connecting members configured to be inserted and fastened in the passages of two adjacent ones of the bone fixation elements; wherein:    the bone fixation device has a plane of symmetry, and the connecting members are arranged parallel to the plane of symmetry.    
     
     
         2 . The device of  claim 1  wherein the bone fixation elements are provided with a blocking element by means of which the mobility of connecting members inserted in the passage relative to the bone fixation element may optionally be fastened and released.  
     
     
         3 . The device of  claim 1  wherein the bone fixation elements are selected from among the following group: bone screws, bone retractors, and bone plates.  
     
     
         4 . The device of  claim 1  wherein the passage is a peripherally closed channel.  
     
     
         5 . The device of  claim 1  wherein the passage is a peripherally open channel in the form of a groove having a U-shaped profile.  
     
     
         6 . The device of  claim 1  wherein the connecting members are rod-like having a round cross-sectional profile.  
     
     
         7 . The device of  claim 1  wherein the number of connecting members ranges from four to seven.  
     
     
         8 . The device of  claim 1  wherein the diameter of the passages and the diameters of the connecting members correspond to one another such that the connecting members are received in the passages in positive engagement.  
     
     
         9 . The device of  claim 1  wherein the cross section of the passages is one of polyhedral, square, rectangular, or triangular.  
     
     
         10 . The device of  claim 1  wherein the connecting members inserted in the passage are in contact with one another.  
     
     
         11 . The device of  claim 1  wherein the bone fixation elements are bone screws and the portion to be anchored in the bone is a threaded screw shank, the bone screw having a head in which a passage is in the form of a U-shaped groove, the groove is configured to be closed by a blocking element in the form of a cap such that the displaceability of the connecting members placed in the groove is inhibited.  
     
     
         12 . The device of  claim 1  wherein the surface of the flexible connecting members has a roughened or microstructured pattern.  
     
     
         13 . The device of  claim 1  wherein the surface of the flexible connecting members has a macrostructured pattern.  
     
     
         14 . The device of  claim 1  wherein the surface of the passage has a roughened or microstructured pattern.  
     
     
         15 . A bone fixation method comprising: 
 anchoring a bone fixation element on or in each of a number of bones or bone fragments via an anchoring portion of the bone fixation element, the bone fixation element also having a passage arranged symmetrically with respect to the anchoring portion;    inserting two or more longitudinal, flexible connecting members into the passages of two adjacent bone fixation elements; and    closing the passages of the two adjacent bone fixation elements using a blocking element to inhibit the mobility of the connecting members inserted into the passage relative to the bone fixation element, rendering the structure of the adjacent bone fixation elements and connecting members rigid.